The present invention relates generally to electric toothbrushes. More particularly, it relates to an improved powered toothbrush with a replaceable head.
The benefits of brushing one's teeth using motorized toothbrushes are well known, and motorized movement in toothbrushes has been the subject of much recent innovation and design activity. Also, the commercial market has seen the introduction, over the last several years, of many different types of motorized toothbrushes. However, an examination of the available technology shows a tendency toward increasingly complex, expensive, and non-commercially feasible methods of achieving motorized motions in the bristles and heads of toothbrushes to aid in more effectively cleaning one's teeth.
The commercial marketplace has become divided into two price markets. On the higher priced end are some of these more complex motorized toothbrushes that provide various motions to the bristles and brush head. The lower end of the market has become the province of very simple motorized toothbrushes that only vibrate through the use of an offset weight attached to the motor shaft, and which provide very little true additional cleaning benefit with their use, since no vigorous motion is transmitted to the cleaning surface of the brush. The vibrations are also very uncomfortable to the hand and act as a disincentive to brush one's teeth for an adequate time.
Numerous electric toothbrushes have been developed over the years. Some known devices are shown in U.S. Pat. Nos. 5,070,567; 5,186,627; 5,274,870; 5,341,534; 5,378,153; and 5,732,433. The intention of the present invention is to provide a low cost, effective, ergonomically correct, motorized toothbrush which has an easily replaceable brush head. Thus, the user can re-use the toothbrush simply by replacing the brush head after the brush head wears out, or several users can use the same handle with several different toothbrush heads.
Various connection structures for linking the brush head to the motor have been suggested, all with varying degrees of success. Any such structure needs to provide a reliable communication of motorized movement to the brush head from the motor, and yet be easily and repeatably attachable and removable, without debilitating the connection integrity over time. Those prior art structures requiring flexible plastic or “living hinge” components of the shaft assembly that are suspect in this regard due to their normal weakening from repeated flexing, wear or age. The subject invention seeks to provide a linking structure that minimizes these prior art problems by providing a connection assembly that provides a reliable and secure connection without having to repeatably flex system components to an undesirable extent, and where the drive shaft is biased from a side disposed spring operating on the shaft instead of comprising a part of the shaft.
Accordingly it has been considered desirable to develop a new and improved electric toothbrush which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.